SEER Inquiry System - Question 20180057 Details

Instruction number 1 under the Coding Multiple Histologies instructions states to code histology when the histology is described as subtype, type or variant. The general rules do indicate we can code the histology identified as type, but when applying the H Rules, it seems an argument could be made for either H1 or H3. H1 applies if you ignore the diagnosis of carcinoma and only code the histologic type: urothelial carcinoma. However, the rules do seem to imply that you take all histologies into account (e.g., code the subtype/variant when there is a not otherwise specified (NOS) and single subtype/variant). Following this logic, Rule H3 seems to be the only rule that fits, and one would code the subtype/variant urothelial carcinoma when the diagnosis is carcinoma NOS, histologic type: urothelial carcinoma.

The problem is that urothelial carcinoma is not a subtype/variant of carcinoma (NOS) per Table 2. The entry for Carcinoma NOS in Table 2 states, Subtypes of carcinoma NOS include adenocarcinoma and all subtypes/variants of adenocarcinoma. To some, urothelial carcinoma is a more specific type of carcinoma; however, urothelial carcinoma is not also listed as a subtype of carcinoma or of adenocarcinoma; only adenocarcinoma is categorized as a subtype of carcinoma. Consistently applying the rules becomes an issue when rules are interpreted in different ways. Should this Table be amended to include urothelial carcinoma as a subtype/variant of carcinoma NOS with the same caveat given to adenocarcinoma in Table 2?